As a laser processing apparatus that conveys and works a glass substrate for producing a liquid crystal display, there is known a crystallization apparatus that crystallizes an amorphous silicon film by a laser.
Conventionally, in the crystallization apparatus, there is proposed a technology of emitting the laser to the amorphous silicon film while filling the vicinity of a laser emitter with an inert gas.
For example, Patent Literature 1 proposes a method of providing a gas injector and an edge-portion straightening surface that extends in a scanning direction, and appropriately securing an atmosphere from the vicinity of the laser emitter to the periphery in the scanning direction by making the gas injected from the gas injector flow between the edge-portion straightening surface and the glass substrate.
In Patent Literature 2, nitrogen gas is injected to an emission portion by a swing nozzle, so that a nitrogen gas atmosphere is secured.
In Patent Literature 3, the interior of a vacuum chamber is in a vacuum or nitrogen (atmospheric pressure) atmosphere state, and thereby, the action of substances in the air on a thin non-crystalline semiconductor film during annealing is prevented.